Hi I'm Wondering could anyone shed some light on this. I replaced the thermostat on my e39 525d last week but the car still struggles to get to temperature. If its left ticking over for a while it does eventually, but on the motorway or im [/align]around 70mph for a while it drops back down around the quarter mark :huh: is there another stat that needs to be changed or was it just a dodgey stat ? With the cold months coming in I don't want it running cold. Any help appreciated thanks.[align=justify]